Answer:

Explanation:
Step 1. Calculate the pOH
pOH =-log[OH⁻]
pOH =-log(1.0 × 10⁻⁹)
pOH = 9.00
Step 2. Calculate the pH
pH + pOH = 14.00
pH + 9.00 = 14.00

Answer:
2.5 g
Explanation:
Given data:
Masses of sample = 0.12 g, 1.8 g, 0.562 g
Combine mass of samples = ?
Solution:
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.
0.12 g + 1.8 g + 0.562 g
2.482 g
In given three measurements 1.8 has less number of significant figure after decimal point which is only one digit. Thus the final value must contain one digit after decimal.
we will round of 2.482 g.
2.5 g
because the next digit after 4 is 8 that's why we will round 4 to 5.
Loschmidt's constant is referred to as Avogadro's number (they are the same). Their values are 6.02 times 10 to the -34 power.
Answer:
1. B 2. D 3. Jon could test which animals like certain foods.
Answer:
MgSO4. 7H2O
There are seven water molecules attached to the hydrated salt.
Explanation:
From the equation;
Number of moles of hydrated salt = number of moles of anhydrous salt, we obtain:
Mass of hydrated salt/ molar mass of hydrated salt = mass of anhydrous salt/ molar mass of anhydrous salt
From the question;
Mass of hydrated salt = 1.000g
Molar mass of hydrated salt = 120.366 +18x gmol-1
Mass of anhydrous salt= 0.488g
Molar mass of anhydrous salt= 120.366 gmol-1
Substituting into the equation above;
1.000/120.366 +18x = 0.488/120.366
1.000/120.366 +18x = 0.004
1.000= 0.004 (120.366 +18x)
1.000= 0.48 + 0.072x
1.000 - 0.48 = 0.072x
0.52= 0.072x
x= 0.52/0.072
x=7
Therefore the hydrated salt is MgSO4. 7H2O